William r



(No Model.)

W. R. PATTERSON.

ELECTRIC LICHT CONDUCTOR.

N0. 309.2416. Patented DCC. 16, 1884.

UNITED STATES PATENT OFFICE.

VILLIAM E. PATTERSON, OF CHICAGO, ILLINOIS, ASSIGNOR TO THE VEST- ERN ELECTRIC COMPANY, OF SAME PLACE.

ELECTRIC-LIGHT CONDUCTOR.

SPECIFICATION forming part of Letters Patent No. 309,246, dated December 16,1884.

Application filed July 1S, 1R84.

vTo @ZZ 107mm, t may conce/"m:

Be itknown thatl, WILLIAM It. Pirrrnnson, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a certain new and usefulj Improvement in Electric Light Conductors (Case 35,) of which the following is a full, clear,

concise, and exact description, reference being had to the accompanying drawings, forming a part of this specification.

My invention relates to underground electric conductors, and more especially to such as are used in incandescent systems of electric lighting, in which two conductors only are ineluded in the saine cable, while the lamps are arranged in multiple arc.

My invention consists in placing the two conductors concentric, and in connecting the different sections of cable together, so that connection may be made readily at any section with the branch or cross wire including the lamps.

My invention is illustrated inthe accompanying drawings, in which Figure l is a longi- 2 5 tudinal sectional View of my electric cable, the ends of two sections being united so as to af ford facilities for making connection with a branch or cross wire which is to contain the lamps. Fig. 2 is an end view of the cable. 3o Fig. 3 is a sectional view taken upon line x .r

of Fig. 1.

Like -parts are indicated by similar letters of reference in the different figures.

The central conductor, a, may be a copper 3 5 wire of such size as maybe desired. The outer conductor, b, is in the form of a tube, watertight, preferably of brass or copper, and should be of about the same conductivity as the inner conductor. The pipe c is preferably of iron. 4o An outer protecting-pipe of lead instead of the iron pipe may be used, however, with a nipple soldered to the end for making connections with the T- pieces. Between the two conductors I place the strips cl, preferably of wood. 4 5 These strips are preferably three in number,

and are designed to hold the wire at the center of the conducting-tube. The two conductors are thus held concentric. Between the outer conductor, I), and the pipe c, I provide 5o similar wooden strips, c. The spaces between (No model.)

the strips are filled with some insulating substance like asphalt, forced in hot. The outer conductor is thus insulated from the pipe, and the two conductors from each other.

The cable may be made at the factory in seetions of about thirty feet each, each section containing two lengths of iron pipe. \Vhen the cable is laid, the sections must be united, and means provided for making connection with the incandescent lamps, which are to be placed in multiple arc-that is, in small wires which connect from one main conductor to the other.

The T- coupling j" may be provided with the bushings gli, of such size as may be necessary to tit the pipe ofthe cable. The T- coupling i, which unites the sections of the tube b, which forms the outer conductor, is of such size that it may be placed within and insulated from the outer coupling, j', by the hard-rubber rings or bushings L'. The sleeve Z forms the connection between the sections of the conductor c. This sleeve should besoldered to one of the sections, so that when the sections of cable are united the sleeve may come between the two sections of conductor a, as shown in Figs. l and 3. If the central conductor is large enough, one of the opposing ends may be provided with 'threads of the saine pitch as the threads upon the two pipes, and united by a T similar to the one which connects the tubular conductor. The pitch of all the threads being the same, one section may be screwed into another, and all the connections formed simultaneously. The outlets of the Ts f and t' may be plugged, eX- cept when used to afford facilities for making a cross or connection between the conductors c and I).

In order to bring outbranches from the conductors a and b, I rst screw a bushing, like bushingg or 7L, into the outlet of the T-piece j'. I then screw in a short piece of cable, the pipe of which fits the inner thread or screwof the bushing, while the tube which forms the outer conductor screws into the T fi, and the central wire comes into the socket m,which is provided, as shown, upon the sleeve Z. The socket m may be tapped out, if desired, so as to fit a screw which may be provided upon the end of the inner conductor of the piece of ca- IOO ble. In this manner a branch or half connection of any desired length may be made with each of the conductors. These branches may be connected in any well-known way with the wire containing the lamps.

It is evident that the pieces j' and fi niay be inade L-shaped,with such inodiiications in the different parts of the conducting pieces as would readily suggest themselves to an ordinary mechanic, and thus the direction of the cable may be readily changed.

If no facilities for making1 half-connections with the conductors are required, concentric couplings may be used instead ot' the Ts f and i.

I claiml. The combination, in a telegraph-cable, with two concentric conductors inclosed within a pipe, and insulated therefrom and freni one another, ofthe T- piece i within the T- piece] and insulated therefroin,whereby two sections of cable may bejoined, while branch or half connections inay be niade with the difierent conductors, substantially as and for the purpose specified.

2. The conibination,with the sections of cable provided with the tube b, and the wire c, placed concentric and insulated by the strips or pieces d and c, of concentric couplings whereby two sections of cable inay be united and the insulation of the concentric conductors maintained, substantially as and for the purpose specilied.

3. The combination, with the pipe and concentric conductors ol'l a telegraph-cable, o1' concentric couplings provided with threads of the saine pitch, whereby two sections of cable nlay be joined and tlre insulation ot' the conductors maintained, substantially as and for the purpose specified.

In witness whereof l hereunto subscribe my naine this 15th day of July, A. D. 1884-.

VILLIAM lt. PATTERSON. 'Witnessesz GEORGE l. BARTON, H. FRANKFURTER. 

